1. Field of the Invention
The present invention relates to a gamut mapping apparatus and method, and more particularly, to a gamut mapping apparatus and method, by which input image data of a wide gamut can be reproduced as image data of a gamut of an output device without distortion by segmenting the gamut of the output device into a core gamut and a surround gamut.
2. Description of the Related Art
To meet gradually increasing user's desire for digital image apparatuses with a variety of functions and high quality performances, such as monitors, scanners, printers and so on, such digital image apparatuses adopt different color spaces or color models depending on fields of the application.
A color model is classified into a device-dependent model and a device-independent model. Typical device-gamut dependent color spaces include an additive color space model such as RGB(Red Green Blue) and a subtractive color space model such as CMYK(Cyan Magenta Yellow Black). Exemplary device-independent color models include CIE L*a*b, CIE XYZ, and CIE LUV. The CIE L*a*b color model is set by the International Commission on Illumination (ICI), which defines lighting standards. The CIEXYZ color model expresses RGB values as a set, X, Y, Z, of different values, all having positive signs. Generally, the X, Y, Z values are referred to as tri-stimulus.
To reproduce input image data of a wide gamut in an output device for outputting narrow gamut image data without distortion, gamut mapping is needed. There have been numerous known techniques of gamut mapping.
First, there has been proposed a gamut mapping method using a look-up table (LUT). According to the proposed method, a LUT for a narrow gamut is previously generated and a LUT for a wide gamut is then generated from the LUT for narrow gamut using interpolation. Thus, it is difficult to achieve accurate gamut mapping from the narrow and wide gamuts to a gamut of an output device.
Another known gamut mapping method is to use a color adjust function, in which gamut compression is performed throughout a gamut of an output device without segmenting the gamut. Thus, it is difficult to accurately reproduce remaining gamut data, excluding a portion corresponding to a narrow gamut of the output device from a wide gamut of an input image.